MiWay debits my account even though I cancelled the product insurance

Miway has debited my account for I product that I cancelled. This is after they were pathetic with their service. I had requested a number of times via telephone and email that they correct the address for Building Cover (MiPlace) and three consultants later nothing was updated accordingly. So I went with another service provider and cancelled with MiWay on the 11th of August. Now they have debited my account and I would like a refund.